Variable-step-size adaptive power allocation algorithm for infrared wireless communication

In order to further enhance the system capacity under certain restrictions of transmitter power and bit error rate (BER) in infrared wireless communication, a novel variable-step-size (VSS) adaptive power allocation algorithm was proposed, which was based on selecting the best modulation technique that costed minimum distribution of power per bit (more bits can be assigned one time). By analyzing the distribution principle and on the basis of the established model, the performance of VSS algorithm was calculated and compared with the ideal water-filling algorithm and traditional simple rate (SR) solution. Simulation results show that under the same circumstance, the new VSS algorithm follows the ideal capacity curve much smoother and allocates the available Tx power much more effectively than the SR solution. Thus, the VSS algorithm has a certain significance when applied in indoor wireless optical communication.